To sum up: The tendency to cost share anything will be influenced by:
In my group (3 Dutch pilots) each pilot pays his own flying but all other costs – landing fees, coffee, meals, taxis, car rental etc are added up and then equally split. Works for us.
Peter (#31):
The main thing which makes cost sharing hard in FAA-land, or in any N-reg worldwide, is the Common purpose rule.
The operations which are the subject of this thread involve “a holding out of a willingness to transport persons or property from place to place for compensation” which makes the operator a common carrier (FAA AC 120-12A).
Operating as a common carrier is a great deal more complicated than complying with the simple common purpose interpretation. It requires FAA safety authority and Part 135 compliance, an appropriate level of insurance, TSO authorisation for operations in the EASA Member States, international economic authority from US DOT and overseas counterparts (who rarely grant cabotage rights), subscription to the IATA Intercarrier Agreement, the carrier must be a US citizen, exclusive use of one aircraft, an aircraft conformity inspection, hazmat training, an FAA approved drug & alcohol program, additional pilot testing by FAA, ad nauseam.
Note that the conditions triggering the common carrier designation have nothing to do with pilot certificate privileges. This distinction is clearly and carefully explained in the aforementioned interpretation to MacPherson.
Graham (#29):
“If the CAA were to operate the same rule as the FAA then I guess those flights would be illegal (to fly or to log?)”
The position on flight time as compensation is intended to give FAA the opportunity of enforcement action against private pilots offering operations like an air taxi service. As written, 61.113 does not explicitly prohibit a pilot offering regular flights which have the character of an on-demand or scheduled service on an at-cost basis. The FAA interpretation of flight time as compensation can help to bring such operations under the rules for common carriers.
Peter wrote (#06):
The FAA “holding out” rule may apply. This does not say that doing a flight for nothing is an exemption although one would hope that a free flight would be ok
Care must be taken to ensure free air transportation is not offered in the hope of some future gain. See legal interpretation of 18 Mar 2013 to John L. Hancock from Mark W. Bury, Acting Assistant Chief Counsel, and of 9 Jul 2014 to Larry Williams from Mark W. Bury, Assistant Chief Counsel, both citing Blakey v. Murray, NTSB Order No. EA-5061 (Oct. 28, 2003).
Administrator v. Murray, NTSB Order No. EA-5061 (2003):
There is no evidence that respondent received any money
directly. … Nevertheless, compensation need
not be direct nor in the form of money. Goodwill is a form of
prohibited compensation. Administrator v. Blackburn, 4 NTSB 409
(1982).
Offering free flights indiscriminately through a flight-sharing platform may have the advantage of overcoming a reservation in Administrator v. Mims, 7 NTSB 850 (1991), cited with added emphasis by Administrator v. Murray:
[A] finding that some prospective economic advantage inured
to respondent … is not precluded by … [a] credibility
determination with respect to the respondent’s subjective
intent…. The subjective intent relates to the actor,
whereas the objective result relates to the act itself. It
is only natural that good will results between individuals
and businesses when a party accommodates and assists
another, and it is unlikely that a free ride would have been
given to any stranger off the street who happened by…
The interpretation of goodwill as potential compensation is continued in Administrator v. Wallace, NTSB Order No. EA-5461 (2009):
In Administrator v. Clair Aero, Inc., NTSB
Order No. EA-5181 at 11 (2005), we stated that, “intangible
benefits, such as the expectation of future economic benefit or
business, are sufficient to render a flight one ‘for
compensation or hire.’” In Clair Aero, we cited several cases
in which we had previously recognized this interpretation,
including Administrator v. Blackburn, 4 NTSB 409 (1982), which
the Ninth Circuit subsequently affirmed. Blackburn v. NTSB, 709
F.2d 1514 (9th Cir. 1983). We also note that in Administrator
v. Wagner, NTSB Order No. EA-4081 at 6 n.11 (1994), we stated as
follows:
It is well-established that “compensation,” which is
one of the elements of “common carriage,” need not be
monetary. Intangible rewards such as good will or the
expectation of future economic benefits——both of which
would likely have resulted from the flight if [the
respondent] had not been charged——can also constitute
“compensation.”
Care must be taken to ensure free air transportation is not offered in the hope of some future gain
For many, that rules out flying with female passenger(s) 
There is a subtle scenario here: the FAA common purpose rule relates to private pilot privileges. The obstacle to Wingley-like operations arises from operating certificate requirements independently of pilot certificate privileges.
The distinction is important because operations may be done outside US using other than a US pilot certificate.
So, someone flying an N-reg by relying on 61.3 and not relying on any US papers (not even a 61.75 piggyback PPL) may be legal to cost share in breach of the FAA rules.
OTOH, this pilot may still breach local law restrictions applying to the aircraft registry e.g. the UK CAA “valuable consideration” rule which is exempted (via the ANO) only for EU-regs.
While you’re basically correct, @Peter, it’s a little more involved than that wrt N-Reg. With certain exceptions (local sightseeing, aerial photography, etc) you cannot operate under part 91 without an Operators Certificate. Even as a commercial pilot, you could not carry pax from A to B w/o such a cert.
Even local sightseeing requires a Letter of Agreement from the local FSDO. I have no idea how that would work out for non-US operations, not at all I suspect. And an LOA is very restrictive, the most important restriction being that you can’t end the flight at an airport other than the one you started at. Also there is a limited radius of operation, 25 nm iirc.
NCYankee wrote:
his might also apply when flying an N registered aircraft and using a 61.75 pilot certificate.
How about flying a N registered aircraft with an EASA license (in the country of issuance)?
How about a N registered aircraft with a FAA CPL, but under Part91?
So far I’ve refused any contribution to flying from people I take along, and intend to keep it this way, but would like to know what is OK, what is borderline, and what is verboten.
tmo wrote:
How about a N registered aircraft with a FAA CPL, but under Part91?
The CPL alone doesn’t help you here, you also need a Letter of Authorization for the airplane from the FAA.
Other than that, the FAA rules are pretty clear:
- advertising (‘holding out’ in FAA legalese) is verboten
- the pilot must pay his/her equal share of the flight (half, third, whatever)
- and now the kicker: everyone on board must have a common purpose for the flight. Which means: 4 friends are going to a football game in a different town: cost sharing allowed. Same flight, but two go to a concert and the other two to the football game: cost sharing verboten.
